The present invention relates to the field of threading devices and more particularly to such devices utilizing twisted wire in combination with thread strands to form a needle or pointed end at one or both ends of a thread. Cobblers, saddlemakers, upholsterers, and others have long been acquainted with the problem of threads separating from the attached needle during sewing operations. Many attempts have therefore been made to overcome this problem by providing a more secure attachment between a needle or "inductor" and the attached thread.
Often, shoemakers and saddlemakers utilize a relatively thick thread that is comprised of several waxed thread strands. This thick thread is attached to a twisted wire or "bristle" that tapers to a point. The twisted wire is connected to the thread through spaces left between the wound wire. The thread is inserted through the wire spaces. Then the wire is tightened by further twisting about the thread. The difficulty presented in this situation is that a free end of the thread is exposed and will often catch as the wire "needle" is pulled through a heavy material.
An example of a wire needle and its attachment to a thread as basically described above, is given in U.S. Pat. No. 342,725 to W. B. Arnold granted May 25, 1886. Arnold discloses a "waxed end" that is comprised of intermingled wires and thread strands. The end is prepared by laying out the thread strands one next to another with loose ends matching longitudinally. A number of wires are then placed between the strands so that their lengths overlap a portion of the strands but extend beyond the strand ends. The strands and loose wires are then gathered and twisted together so that the wires will be interwoven with the twisted strands. The strand ends will be situated rearwardly of the wire "cable" end that is formed from the twisted portions of the wires that extend beyond the ends of the strands. This structure and method for producing this structure facilitates continuous production of successive strands interconnected by the wire "needles" in a continuous integral length, so that a user may cut successive lengths from a roll.
The difficulty presented with this arrangement is that strands ends are exposed and face the material into which they are to be pulled. Therefore, these ends may catch on the material and be pulled rearwardly away from engagement with the interwoven wires. At best, the strand ends will fray and enlarge the effective diameter of the threading unit. Under more strained conditions, the thread strands will completely separate from the needle in the midst of a sewing operation.
U.S. Pat. No. 386,723 to J. T. Smith, issued July 24, 1888, discloses another form of "wax end" needle. In this form, a single wire is doubled over onto itself and is twisted together, leaving three successive slits along its length between windings. The thread is attached to this needle by weaving a free end thereof through the three slits. Once this is done, the slits may be closed by twisting the wire end tightly about the thread at the three locations. The forward end of the thread is exposed, facing the material during sewing operations. Thus, it may also fray and enlarge the effective cross-sectional size of the entire threading unit. This device, however, does provide a reasonably good connection between the wire needle, and cord or thread.
A very similar device is also shown in U.S. Pat. No. 183,173 granted to H. M. Jenkins and issued on Oct. 10, 1876. The disparity between Jenkins' and Smith's devices is that Jenkins' utilizes a pair of wires wrapped about each other and a single aperture or slit through which the thread is attached. Operational features of the Jenkins' needle or "bristle" are similar to that provided by Smith.
It is a primary object of the present invention to provide an integral needle and a multi-strand thread arrangement whereby no loose thread filament ends may possibly face the material to be sewn.
Another object is to provide such an integral unit that tapers from an effective cord diameter to a reduced wire cable end to thereby enhance threading capability.
A still further object is to provide a threading device in which the effective cross-sectional size of the "needle" is never greater than the effective cross-sectional size of the thread attached therewith.
A still further object is to provide such a device that is relatively simple in construction and may be quickly and efficiently produced.
An additional object is to provide such a device that may be produced in a continuous length and stored on a spool so successive units may be pulled and cut from the continuous length.
These and still further objects and advantages will become apparent upon reading the following description which, taken with the accompanying drawings, will disclose preferred and alternate forms of the present invention.